Reclosable package

ABSTRACT

THE DISCLOSURE EMBRACES A PACKAGE HAVING A RECLOSABLE LID WHICH IS RELEASABLY SECURED TO THE BODY OF THE PACKAGE BY A PRESENCE SENSITIVR ADHESIVE; A PEELABLE FILM IS INTERPOSED BETWEEN THE PACKAGE AND THE PRESSURE SENSITIVE ADHESIVE.

y 9, 1972 H. B. MILLER Re. 27,361

RECLOSABLE PACKAGE Original Filed March 31, 1965 2 Sheets-Sheet 1.

INVENTOR ATTORNEKS' y 9, 1972 H. B. MILLER Re. 27,361

RECLOSABLE PACKAGE Original Filed March 31, 1965 2 Sheets-Sheet 2INVENTOII ATTORNEYS United States Patent 27,361 RECLOSABLE PACKAGEHarmon B. Miller, 1095 W. Conway Drive NW., Atlanta, Ga. 30327 OriginalNo. 3,272,422, dated Sept. 13, 1966, Ser. No. 444,271, Mar. 31, 1965.Application for reissue Mar. 6, 1970, Ser. No. 17,351

Int. Cl. B65d 43/02 US. Cl. 229-43 7 Claims Matter enclosed in heavybrackets II] appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE The disclosure embraces a package having areclosable lid which is releasably secured to the body of the package bya pressure sensitive adhesive; a peelable film is inter- Zosed betweenthe package and the pressure sensitive adeszve.

The present invention relates to an improvement in a reclosable packageand more particularly to a package having a reclosable lid releasablysecured to the body of the package by a pressure sensitive adhesive.

The principal object of the present invention is to provide a packagehaving a lid member which is secured to the body of the package by apressure sensitive adhesive, but in which the pressure sensitiveadhesive is initially not exposed so as to interfere with filling andclosing of the package.

This object can be better understood by consideration of one type ofpackage for which the present improvement is useful, i.e. packages whichcomprise a preformed cup or receptacle of transparent plastic sheetmaterial such as Saran or polyethylene, and a lid. A package of thistype is shown herein in FIGURE 2 and comprises a bottom and sides. Thereis a flange extending laterally outwardly from the sides, and asubstantially flat lid rests against the flange to close the package.

In order for the package to be used for perishable foods, it ispreferable for the lid to be hermetically sealed to the flange. However,for the convenience of the consumer, it is desirable that the lid beeasily removable and replaceable in the event that only part of thecontents of the package are to be removed at one time.

Pressure sensitive adhesives are available which are capable ofproviding this kind of seal. A pressure sensitive adhesive is ordinarilyemployed as a coating or mass on a backing material and is normallytacky. It will stick to most surfaces but may be peeled olf non-fibroussurfaces easily without leaving any residue on the surface. The adhesivemass is more strongly bonded to the backing material and is notseparated from it when it is peeled off the non-fibrous surface.

It will be appreciated therefore that a pressure sensitive layer on alid would permit the package to be closed, reopened and reclosed as manytimes as desired by the consumer. However, this type of adhesive has thedisadvantage that the ease with which it sticks to most surfaces can beinconvenient when the package is initially filled and closed by amanufacturer or packer. Automated packaging machinery operating at highspeed can more readily handle packaging materials which have no tendencyto stick to each other or the equipment used to rocss them. For example,in a stack of lids of the type described above, it would be undesirablefor the individual lids to tend to stick to each other as they would ifthey were coated with pressure sensitive adhesive. It is possible toapply a coating to the back of the lids, re.

a backsize coating of the type used on pressure sensitive adhesive tape,which will prevent forming a permanent bond between the lids. However,the lids would nevertheless stick to each other in the same manner asthe successive layers on a roll of pressure sensitive tape, and wouldhave to be pulled apart as they are used. In the case of vacuumpackaging, the lid could not be placed on the package prior toevacuation because it would stick and would not lift off the package topermit outflow of air.

Accordingly, there is a need for a pressure sensitive adhesive seal forpackages which is rendered inoperative while the package is being filledand closed initially, prior to sale. This object is achieved by thepresent invention in which a pressure sensitive adhesive is used on apackage lid (or other package closing member), but it is ini tiallycovered by a peelable film member. When the package is closed, thepeelable member is permanently sealed (e.g. heat sealed) to the package.Thereafter, when the lid is removed by the purchaser, the pressuresensitive adhesive on the lid lifts away from the peelable film. The lidcan be rescaled easily by lightly pressing the adhesive against thepeelablc film, and it can be reopened and closed repeatedly in the samemanner.

The invention will be better understood by consideration of thefollowing detailed description of preferred embodiments, reference beingmade to the drawing, in which:

FIGURE 1 is a perspective view of a lid embodying the sealing featuresof the present invention.

FIGURE 2 is a perspective view of the components of a package which maybe sealed in accordance with the invention.

FIGURE 3 is a cross-section of a lid along the lines 33 of FIGURE 1.

FIGURE 4 is a perspective view of another form of package.

FIGURE 5 is a cross-sectional view of a receptacle and lid embodying thesealing features of the present invention.

Referring to FIGURES l and 3, the lid comprises a circular board 1having a tab 2 extending from one side. The board may be paper, printedwith labeling information, or it may be transparent plastic to permitinspection of the contents of the package. The undersurface of the boardis coated with a layer of pressure sensitive adhesive 3. The coating isin the shape of a narrow ring around the edge of the lid, for sealing tothe edge of a cup. One side of a peelable film 4 is adhered to thepressure sensitive adhesive coating, and it is coated on its othersurface with a heat seal material 5. The peelablc film 4 and the heatseal coating 5, also are ring shaped, and are at least as wide as thepressure sensitive adhesive coating to substantially completely coverit.

The pressure sensitive adhesive may be any available pressure sensitiveadhesive mass, its composition not being an element of the presentinvention. It is well known to those skilled in the art that pressuresensitive adhesive coatings possess a fourfold balance of tackiness,cohesion, elasticity and stretchiness. This balance is achieved forexample, in a blend of rubber and a resin, the rubber providing cohesionand elasticity, and the resin providing tackiness and modification ofstretchiness and elasticity. It also is known to use certain acrylatepolymers in the mass, which inherently possess the necessary fourfoldbalance of properties. Materials of this type are readily availablecommercially, and manufacturers will provide information on materials tobe used, taking into account the composition of the board 1 and thepeelable film 4. Where necessary, a primer coating may be used on theboard, under the pressure sensitive adesive, to assure a firm bond, anda backsize coating may 2 used on the peelable film. It also will beunderstood rat, where food products are to be packaged, it may beecessary to take into account the toxicity of materials sed.

The heat seal coating is an optional feature, tobe sed only where thepeelable film does not readily heat :al to the package. Where thepackage is, say, polythylene or polystyrene, the same material may beused )r the peelable film and a heat seal coating may be ecessary.

For convenience in handling, it may be desirable to mploy a peelablefilm 4 of the same size and shape as re board 1. The [This] innerportion, within the dered ring, may then be separated with a die cutter.If 1e pressure sensitive adhesive is coated in a ring, only, 5 shown,the film will drop out. If the pressure sensitive dhesive is coated overthe entire surface of the board, 1e inner part of the film will simplylift olf with the board hen the package is opened.

This embodiment is illustrated in FIG. 5 wherein a zceptacle 8' which issimilar to the receptacle illustrated 1 FIG. 2 is provided with flange 9to which a secured portion 4a of a film by means of a heat seal materialPortion 4b is separated from portion 4a by being cut s at 4'. Theclosure member 1 which is formed with tab 2 is provided on its undersidewith the pressure znsitive adhesive layer 3 over its entire surface.

Several types of package may be sealed in accordance ith the invention,for example those shown in FIG- IRES 2 and 4. The package in FIGURE 2comprises a up 6 adapted to hold, for example, sliced luncheon met. Thecup has a bottom 7, sides 8 and a lateral ange 9 extending from thesides. A lid 10 is shown bove the cup, which will overlie the flange 9when the ackage is closed. The adhesive and heat seal coatings .nd thepeelable film are not shown in this view of the .d, for simplicity, butit will be appreciated that they my be the same as on the lid shown inFIG. 1.

The package shown in FIGURE 4 is of a size and hape for slices of baconand illustrates a form of the IVGIItiOIl in which only a part of theclosure is resealble, the remainder being permanently sealed. Thisackage comprises a rectangular base member which my be a piece ofcardboard. Two edges of the base aember are turned back to overlie thebase, as indicated t 21 and 22, the turned over portions being sealed tohe base by adhesive at the ends of the package, and this dhesive may bepressure sensitive if desired.

The closure is a piece of flexible transparent plastic .lm 23 such aspolyethylene. This film, which will be eferred to as the lid, forconvenience, is sealed at its dges to the underlying board. However,only a porion of the edge of the lid is sealed to the base 20 with hepressure-sensitive adhesive reclosable construction of be presentinvention. The other portions of the edges .re permanently sealed to thebase.

The portions which are permanently sealed are indiated at 24, 25 and 26and are over the turned over edge ,2 of the base. Other portions of theedge are sealed vith pressure sensitive adhesive and a heat seal in thenanner described with respect to the lid in FIGURE 1.

The permanent seal may be achieved, for example, by imply omitting thepressure sensitive adhesive and heat ealing the peelable film to thelid. If necessary, heat eal coatings may be used on both side of thepeelable ilm for this purpose.

The package shown in FIGURE 4 is particularly useul when the lid memberis a flexible film. Because of he limpness of the film, the purchasermight find it difii- :ult to replace the lid. However, if the film isonly ?olded back, and is not completely removed, the film vill bereplaced more easily. By using this construcion, the customer is notable to peel the lid off completely without tearing it an d thereforewill only fold it back.

It will be appreciated that various materials may be used for the lidand the peelable film, and the other parts of the package, includingpaper and plastics such as Saran, polyethylene, polypropylene,polystyrene, polyethylene terephthalate (Mylar) etc. Where paper isused, it may be coated with a barrier layer such as Saran, and, if thepaper is to be heat sealed, it may require a coating of heat scalableplastic in the heat seal areas.

The permanent seal may be achieved by heating the members to be sealedwhile they are pressed together. Heating sealing is widely used industryand forms no part of the present invention. Information in temperaturesto be used and equipment is readily available. It also is possible touse other types of permanent seal, for example the application of asolvent to plastic surfaces, or the wetting of a water soluble adhesive,through these are less convenient than heating sealing. The invention isapplicable to a wide variety of packages. It will appreciated that theconcealed pressure sensitive adhesive construction can be used for anytype of package closure member. It also will be understood that thepressure sensitive adhesive can be applied to the package itself, ratherthan the closure, although this construction is somewhat less desirable.That is, it is preferable to have the pressure sensitive adhesive out ofthe way when the contents of the package are removed. Various otherchanges may be made in materials, details of construction and mode ofoperation, without departing from the scope of the invention, as definedin the appended claims.

I claim:

1. A package comprising a receptacle having an opening for receiving andremoving a product and a closure member adapted to at least partiallyclose said opening, said closure member having a coating of pressuresensitive adhesive mass on at least a portion of the area thereof whichis adjacent said [package] receptacle, and a peelable film, overlyingsaid pressure sensitive adhesive, which is permanently scalable to said[package] receptacle and from which said closure member can be removedWithout substantial transfer of pressure sensitive adhesive mass to saidfilm, whereby upon permanently sealing said film to said [package]receptacle said closure member may be removed and then rescaled to the[package] receptacle, said peelable film being cut into two portions,both overlying said pressure sensitive adhesive so that, when one ofsaid portions is removed with said closure member, the other portion canremain sealed to said receptacle.

2. A package comprising a receptacle having an opening for receiving andremoving a product and a closure member adapted to at least partiallyclose said opening, said closure member having a coating of pressuresensitive adhesive mass on at least a portion of the area thereof whichis adjacent said [package] receptacle, and a peelable film, overlyingsaid pressure sensitive adhesive, which is heat scalable to said[package] receptacle and from which said closure member can be removedwithout substantial transfer of pressure sensitive adhesive mass to saidfilm, whereby upon heat sealing said film to said [package] receptaclesaid closure member may be removed and then rescaled to the [package]receptacle, said peelable film being cut into two portions, bothoverlying said pressure sensitive adhesive so that, when. one of saidportions is removed with said closure member, the other portion canremain sealed to said receptacle.

3. A package comprising a receptacle having an opening for receiving andremoving a product and a closure member adapted to at least partiallyclose said opening, said closure member having a coating of pressuresensitive adhesive mass on at least a portion of the area thereof whichis adjacent said [package] receptacle, and a peelable film, overlyingsaid pressure sensitive adhesive, which is permanently sealed to said[package] receptacle and from which said closure member can be removedwithout substantial transfer of pressure sensitive adhesive mass to saidfilm, whereby said closure member may be removed from and rescaled tosaid receptacle, said peelable film being cut into two portions, bothoverlying said pressure sensitive adhesive, one of which portions ispermanently sealed to said receptacle and the other of which portions isnot sealed to said receptacle, so that said other portion is removedwith said closure member when the receptacle is opened.

4. A package comprising a receptacle having an opening for receiving andremoving a product and a closure member adapted to at least partiallyclose said opening, said closure member having a coating of pressuresensitive adhesive mass on at least a portion of the area thereof whichis adjacent said [package] receptacle, and a peelable film, overlyingsaid pressure sensitive adhesive, which is heat sealed to said [package]receptacle and from which said closure member can be removed Withoutsubstantial transfer of pressure sensitive adhesive mass to said film,whereby said closure member may be removed from and rescaled to saidreceptacle, said peelable film being cut into two portions, bothoverlying said pressure sensitive adhesive, one of which portions ispermanently sealed to said receptacle and the other of which portions isnot sealed to said receptacle, so that said other portion is removedwith said closure member when the receptacle is opened.

[5. A package as set forth in claim 4 in which a portion of the area ofsaid closure member adjacent said receptacle is permanently sealed tothe receptacle, so that on removing the closure member from saidpeelable film, the closure member remains attached to the receptacle][6. A method of closing a package which comprises a receptacle having anopening for receiving and removing a product and a closure member whichat least partially closes said opening, said closure member having acoating of pressure sensitive adhesive mass on at least part of the areathereof which is adjacent said package, and a peelable film, overlyingsaid pressure sensitive adhesive, which is heat scalable to saidpackage, and from which said closure member can be removed withoutsubstantial transfer of pressure sensitive adhesive mass to said film,said method comprising placing said closure member against saidreceptacle and then heating said receptacle and said peelable film toheat seal said peelable film to said receptacle] 7. A package closurecomprising a closure member adapted to at least partially close anopening into a package, a layer of pressure sensitive adhesive mass onsaid closure member in an area thereof which is adjacent said package,and a peelable film, overlying said pressure sensitive adhesive, whichis permanently scalable to said package and from which said closuremember can be removed without substantial transfer of pressure sensitiveadhesive mass to said film, whereby, upon permanently sealing said filmto the package the closure member may be removed and then rescaled tothe package, said peelable film being cut into two portions, bothoverlying said pressure sensitive adhesive so that, when one of saidportions is removed with said closure member the other portion canremain sealed to said package.

8. A package closure comprising a closure member adapted to at leastpartially close an opening into a package, a layer of pressure sensitiveadhesive mass on said closure member in an area thereof which isadjacent said package, and a peelable film, overlying said pressuresensitive adhesive, which is heat scalable to said package and fromwhich said closure member can be removed without substantial transfer ofpressure sensitive adhesive mass to said film, said peelable film beingcut into two portions, both overlying said pressure sensitive adhesiveso that, when one of said portions is removed with said closure member,the other portion can remain sealed to said package.

9. A package closure as set forth in claim 8 including a coating of heatscalable plastic on said peelable film to render said peelable film heatscalable to said package.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 2,719,663 10/1955 Meyer-Jagenberg 229-7 R3,079,057 2/ 1963 Colarusso 22943 X 3,202,271 8/1965 Kirk 206-56 AA2,271,279 1/ 1942 Thomas. 2,805,183 9/ 1957 Higgins. 2,874,836 2/ 1959Wertepny 20678 3,049,224 8/196Q Fredette 206-42 3,149,771 9/ 1964 Rearl.

FOREIGN PATENTS 931,826 7/1963 Great Britain.

DONALD F. NORTON, Primary Examiner US. Cl. X.R. 229-51 SC

